KasmVNC/kasmweb/core/input/mouse.js
2021-03-29 11:54:44 +03:00

277 lines
9.8 KiB
JavaScript

/*
* noVNC: HTML5 VNC client
* Copyright (C) 2019 The noVNC Authors
* Licensed under MPL 2.0 or any later version (see LICENSE.txt)
*/
import * as Log from '../util/logging.js';
import { isTouchDevice } from '../util/browser.js';
import { setCapture, stopEvent, getPointerEvent } from '../util/events.js';
const WHEEL_STEP = 10; // Delta threshold for a mouse wheel step
const WHEEL_STEP_TIMEOUT = 50; // ms
const WHEEL_LINE_HEIGHT = 19;
export default class Mouse {
constructor(target) {
this._target = target || document;
this._doubleClickTimer = null;
this._lastTouchPos = null;
this._pos = null;
this._wheelStepXTimer = null;
this._wheelStepYTimer = null;
this._accumulatedWheelDeltaX = 0;
this._accumulatedWheelDeltaY = 0;
this._eventHandlers = {
'mousedown': this._handleMouseDown.bind(this),
'mouseup': this._handleMouseUp.bind(this),
'mousemove': this._handleMouseMove.bind(this),
'mousewheel': this._handleMouseWheel.bind(this),
'mousedisable': this._handleMouseDisable.bind(this)
};
// ===== PROPERTIES =====
this.touchButton = 1; // Button mask (1, 2, 4) for touch devices (0 means ignore clicks)
// ===== EVENT HANDLERS =====
this.onmousebutton = () => {}; // Handler for mouse button click/release
this.onmousemove = () => {}; // Handler for mouse movement
}
// ===== PRIVATE METHODS =====
_resetDoubleClickTimer() {
this._doubleClickTimer = null;
}
_handleMouseButton(e, down) {
this._updateMousePosition(e);
let pos = this._pos;
let bmask;
if (e.touches || e.changedTouches) {
// Touch device
// When two touches occur within 500 ms of each other and are
// close enough together a double click is triggered.
if (down == 1) {
if (this._doubleClickTimer === null) {
this._lastTouchPos = pos;
} else {
clearTimeout(this._doubleClickTimer);
// When the distance between the two touches is small enough
// force the position of the latter touch to the position of
// the first.
const xs = this._lastTouchPos.x - pos.x;
const ys = this._lastTouchPos.y - pos.y;
const d = Math.sqrt((xs * xs) + (ys * ys));
// The goal is to trigger on a certain physical width, the
// devicePixelRatio brings us a bit closer but is not optimal.
const threshold = 20 * (window.devicePixelRatio || 1);
if (d < threshold) {
pos = this._lastTouchPos;
}
}
this._doubleClickTimer = setTimeout(this._resetDoubleClickTimer.bind(this), 500);
}
bmask = this.touchButton;
// If bmask is set
} else if (e.which) {
/* everything except IE */
bmask = 1 << e.button;
} else {
/* IE including 9 */
bmask = (e.button & 0x1) + // Left
(e.button & 0x2) * 2 + // Right
(e.button & 0x4) / 2; // Middle
}
Log.Debug("onmousebutton " + (down ? "down" : "up") +
", x: " + pos.x + ", y: " + pos.y + ", bmask: " + bmask);
this.onmousebutton(pos.x, pos.y, down, bmask);
stopEvent(e);
}
_handleMouseDown(e) {
// Touch events have implicit capture
if (e.type === "mousedown") {
setCapture(this._target);
}
this._handleMouseButton(e, 1);
}
_handleMouseUp(e) {
this._handleMouseButton(e, 0);
}
// Mouse wheel events are sent in steps over VNC. This means that the VNC
// protocol can't handle a wheel event with specific distance or speed.
// Therefor, if we get a lot of small mouse wheel events we combine them.
_generateWheelStepX() {
if (this._accumulatedWheelDeltaX < 0) {
this.onmousebutton(this._pos.x, this._pos.y, 1, 1 << 5);
this.onmousebutton(this._pos.x, this._pos.y, 0, 1 << 5);
} else if (this._accumulatedWheelDeltaX > 0) {
this.onmousebutton(this._pos.x, this._pos.y, 1, 1 << 6);
this.onmousebutton(this._pos.x, this._pos.y, 0, 1 << 6);
}
this._accumulatedWheelDeltaX = 0;
}
_generateWheelStepY() {
if (this._accumulatedWheelDeltaY < 0) {
this.onmousebutton(this._pos.x, this._pos.y, 1, 1 << 3);
this.onmousebutton(this._pos.x, this._pos.y, 0, 1 << 3);
} else if (this._accumulatedWheelDeltaY > 0) {
this.onmousebutton(this._pos.x, this._pos.y, 1, 1 << 4);
this.onmousebutton(this._pos.x, this._pos.y, 0, 1 << 4);
}
this._accumulatedWheelDeltaY = 0;
}
_resetWheelStepTimers() {
window.clearTimeout(this._wheelStepXTimer);
window.clearTimeout(this._wheelStepYTimer);
this._wheelStepXTimer = null;
this._wheelStepYTimer = null;
}
_handleMouseWheel(e) {
this._resetWheelStepTimers();
this._updateMousePosition(e);
let dX = e.deltaX;
let dY = e.deltaY;
// Pixel units unless it's non-zero.
// Note that if deltamode is line or page won't matter since we aren't
// sending the mouse wheel delta to the server anyway.
// The difference between pixel and line can be important however since
// we have a threshold that can be smaller than the line height.
if (e.deltaMode !== 0) {
dX *= WHEEL_LINE_HEIGHT;
dY *= WHEEL_LINE_HEIGHT;
}
this._accumulatedWheelDeltaX += dX;
this._accumulatedWheelDeltaY += dY;
// Generate a mouse wheel step event when the accumulated delta
// for one of the axes is large enough.
// Small delta events that do not pass the threshold get sent
// after a timeout.
if (Math.abs(this._accumulatedWheelDeltaX) > WHEEL_STEP) {
this._generateWheelStepX();
} else {
this._wheelStepXTimer =
window.setTimeout(this._generateWheelStepX.bind(this),
WHEEL_STEP_TIMEOUT);
}
if (Math.abs(this._accumulatedWheelDeltaY) > WHEEL_STEP) {
this._generateWheelStepY();
} else {
this._wheelStepYTimer =
window.setTimeout(this._generateWheelStepY.bind(this),
WHEEL_STEP_TIMEOUT);
}
stopEvent(e);
}
_handleMouseMove(e) {
this._updateMousePosition(e);
this.onmousemove(this._pos.x, this._pos.y);
stopEvent(e);
}
_handleMouseDisable(e) {
/*
* Stop propagation if inside canvas area
* Note: This is only needed for the 'click' event as it fails
* to fire properly for the target element so we have
* to listen on the document element instead.
*/
if (e.target == this._target) {
stopEvent(e);
}
}
// Update coordinates relative to target
_updateMousePosition(e) {
e = getPointerEvent(e);
const bounds = this._target.getBoundingClientRect();
let x;
let y;
// Clip to target bounds
if (e.clientX < bounds.left) {
x = 0;
} else if (e.clientX >= bounds.right) {
x = bounds.width - 1;
} else {
x = e.clientX - bounds.left;
}
if (e.clientY < bounds.top) {
y = 0;
} else if (e.clientY >= bounds.bottom) {
y = bounds.height - 1;
} else {
y = e.clientY - bounds.top;
}
this._pos = {x: x, y: y};
}
// ===== PUBLIC METHODS =====
grab() {
if (isTouchDevice) {
this._target.addEventListener('touchstart', this._eventHandlers.mousedown);
this._target.addEventListener('touchend', this._eventHandlers.mouseup);
this._target.addEventListener('touchmove', this._eventHandlers.mousemove);
}
this._target.addEventListener('mousedown', this._eventHandlers.mousedown);
this._target.addEventListener('mouseup', this._eventHandlers.mouseup);
this._target.addEventListener('mousemove', this._eventHandlers.mousemove);
this._target.addEventListener('wheel', this._eventHandlers.mousewheel);
/* Prevent middle-click pasting (see above for why we bind to document) */
document.addEventListener('click', this._eventHandlers.mousedisable);
/* preventDefault() on mousedown doesn't stop this event for some
reason so we have to explicitly block it */
this._target.addEventListener('contextmenu', this._eventHandlers.mousedisable);
}
ungrab() {
this._resetWheelStepTimers();
if (isTouchDevice) {
this._target.removeEventListener('touchstart', this._eventHandlers.mousedown);
this._target.removeEventListener('touchend', this._eventHandlers.mouseup);
this._target.removeEventListener('touchmove', this._eventHandlers.mousemove);
}
this._target.removeEventListener('mousedown', this._eventHandlers.mousedown);
this._target.removeEventListener('mouseup', this._eventHandlers.mouseup);
this._target.removeEventListener('mousemove', this._eventHandlers.mousemove);
this._target.removeEventListener('wheel', this._eventHandlers.mousewheel);
document.removeEventListener('click', this._eventHandlers.mousedisable);
this._target.removeEventListener('contextmenu', this._eventHandlers.mousedisable);
}
}